KR20130070043A - Light emitting diode and liquid crystal display device using the same - Google Patents

Light emitting diode and liquid crystal display device using the same Download PDF

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Publication number
KR20130070043A
KR20130070043A KR1020110137163A KR20110137163A KR20130070043A KR 20130070043 A KR20130070043 A KR 20130070043A KR 1020110137163 A KR1020110137163 A KR 1020110137163A KR 20110137163 A KR20110137163 A KR 20110137163A KR 20130070043 A KR20130070043 A KR 20130070043A
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South Korea
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led chip
light
phosphor
diffusion layer
emitting diode
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KR1020110137163A
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Korean (ko)
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전덕진
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엘지디스플레이 주식회사
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Priority to KR1020110137163A priority Critical patent/KR20130070043A/en
Publication of KR20130070043A publication Critical patent/KR20130070043A/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133615—Edge-illuminating devices, i.e. illuminating from the side
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/50—Wavelength conversion elements
    • H01L33/501—Wavelength conversion elements characterised by the materials, e.g. binder
    • H01L33/502—Wavelength conversion materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/52—Encapsulations
    • H01L33/56—Materials, e.g. epoxy or silicone resin
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
    • H01L33/58—Optical field-shaping elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732—Location after the connecting process
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73265—Layer and wire connectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Power Engineering (AREA)
  • Nonlinear Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mathematical Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Led Device Packages (AREA)

Abstract

The present invention relates to a light emitting diode, and more particularly, to a liquid crystal display device using the light emitting diode as a light source.
A feature of the present invention is that the diffusion layer is interposed between the LED chip and the phosphor.
Through this, the light emitted from the LED chip can be prevented from being partially concentrated by the diffusion layer, and since the diffusion layer has a refractive index similar to that of the LED chip, the difference in refractive index between the LED chip and the diffusion layer is reduced, thereby emitting light emitted from the LED chip. The light is totally reflected at the boundary between the LED chip and the diffusion layer to minimize reabsorption or scattering of the LED chip.
Therefore, the amount of light incident on the fluorescent layer can be increased, and the light efficiency can be improved by reducing the light loss.
In addition, the light generated in the fluorescent layer can be prevented from being reabsorbed by the LED chip, thereby improving the light efficiency.
In addition, since the LED chip and the phosphor are positioned to be spaced apart from each other by a predetermined distance, it is possible to prevent the problem that the phosphor is deteriorated by the heat generated when driving the LED chip, and also to prevent the problem of the degradation of the LED due to the degradation of the phosphor. Can be.

Description

Light emitting diode and liquid crystal display device using the same

The present invention relates to a light emitting diode, and more particularly, to a liquid crystal display device using the light emitting diode as a light source.

Recently, the use of light emitting diodes (LEDs), which combines small size, low power consumption, high reliability, and the like, is increasing. Such LEDs are used for various lighting purposes, and the use range of the display units of electronic products, various display devices, and lighting devices of vehicles is gradually increasing.

In particular, LEDs may artificially generate white light to replace fluorescent lamps for general lighting, and LEDs that implement white light are spotlighted as backlight units of liquid crystal displays (LCDs).

Here, in order to implement white light, a plurality of LED chips emitting light of R, G, and B colors may be adjacent to each other, and white light may be realized through color mixing of light emitted from each LED chip. Since the chips have different thermal or temporal characteristics, there is a problem in that the color is changed according to the use environment, and in particular, color uniformity is not realized.

Recently, a method of realizing white light by placing a phosphor on an LED chip and mixing the first emitted light of the LED chip with the second emitted light whose wavelength is changed by the phosphor is widely used.

For example, by placing a yellow phosphor on top of an LED chip emitting blue light, white light is realized by mixing blue and yellow colors.

However, when the white light is implemented using the phosphor, as the phosphor is located close to the LED chip, the phosphor is deteriorated by heat generated when the LED chip is driven, so that the efficiency of the phosphor is reduced or the degradation of the LED is intensified. And therefore, the luminous efficiency of the LED is lowered.

In addition, the difference between the refractive index of the LED chip and the phosphor is large, the light emitted from the LED chip is totally reflected at the boundary of the LED chip and the phosphor, so that some light is reabsorbed or scattered by the LED chip.

Therefore, it causes light loss, which in turn causes a problem of increased power consumption.

The present invention is to solve the above problems, the first object is to provide an LED with improved luminous efficiency, and a second object is to provide an LED without light loss.

In order to achieve the object as described above, the present invention is an LED chip mounted on a substrate; A phosphor positioned on the LED chip to absorb light emitted from the LED chip to emit wavelength converted light; Provided is a light emitting diode interposed between the LED chip and the phosphor and including a diffusion layer including a bead.

In this case, the diffusion layer has a refractive index of 1.5 ~ 2.0, the diffusion layer is made of the beads mixed with the transparent resin.

In addition, the beads are contained in the transparent resin 1 to 3%, the transparent resin is an acrylic transparent resin polymethylmethacrylate (polymethylmethacrylate: PMMA), polystyrene (polysterene), polyurethane (polyuretane), epoxy (epoxy) And silicone resins.

Here, the phosphor is mixed in the transparent resin and positioned on the diffusion layer, the lens is positioned on the phosphor resin or glass material, the phosphor is mixed with silicon made of a lens, or coated on the lens inner wall.

In addition, the LED chip is a blue LED chip, the phosphor is a yellow phosphor, or a phosphor mixed with red and green phosphor, the LED chip is a UV LED chip, the phosphor is red (R), green (G), blue (B) is a phosphor.

In addition, the present invention is an LED chip mounted on a substrate; A phosphor positioned on the LED chip to absorb light emitted from the LED chip to emit wavelength converted light; An LED assembly interposed between the LED chip and the phosphor and including a light emitting diode including a diffusion layer including a bead, and a printed circuit board on which the light emitting diode is mounted; A backlight unit including a light guide plate positioned at one side of the LED assembly, a reflective plate positioned below the light guide plate, and an optical sheet mounted on the light guide plate; A liquid crystal panel mounted on the backlight unit; A backlight unit and a support main body surrounding an edge of the liquid crystal panel; A cover bottom formed in close contact with the support main back surface; It provides an LCD device including a top cover which is bounded by the edge of the liquid crystal panel and assembled to the support main and the cover bottom.

As described above, the diffusion layer is interposed between the LED chip and the phosphor according to the present invention, thereby preventing the light emitted from the LED chip from partially condensing. By having a similar refractive index, the difference in refractive index between the LED chip and the diffusion layer is reduced, and the light emitted from the LED chip is totally reflected at the boundary of the LED chip and the diffusion layer to minimize the re-absorption or scattering of the LED chip.

Therefore, the amount of light incident on the fluorescent layer can be increased, thereby reducing the light loss, thereby improving the light efficiency.

In addition, the light generated in the fluorescent layer can be prevented from being reabsorbed by the LED chip, thereby improving the light efficiency.

In addition, since the LED chip and the phosphor are positioned to be spaced apart from each other by a predetermined distance, it is possible to prevent the problem that the phosphor is deteriorated by the heat generated when driving the LED chip, and also to prevent the problem of the degradation of the LED due to the degradation of the phosphor. It can be effective.

1 is a cross-sectional view of a general LED for implementing white light according to a first embodiment of the present invention.
2 is a cross-sectional view schematically showing the cross-sectional structure of the LED chip of FIG.
3A to 3B are cross-sectional views of a general LED implementing white light according to a second embodiment of the present invention.
4 is a cross-sectional view showing a liquid crystal display device according to an embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

1 is a cross-sectional view of a general LED for implementing white light according to a first embodiment of the present invention, Figure 2 is a cross-sectional view schematically showing the cross-sectional structure of the LED chip of FIG.

As shown, the LED 100 includes an LED chip 120 that emits large light and a lens 150 covering the LED chip 120.

Looking at each of these in detail, first, the LED chip 120 is a portion that substantially emits light, the n-type semiconductor layer 122 for providing electrons and the p-type semiconductor layer 124 for providing holes (hole) It consists of a forward junction of.

The LED chip 120 includes an n-type semiconductor layer 122, an active layer 123, a p-type semiconductor layer 124, an n-type electrode 125, and a p-type electrode 126 stacked on a substrate 121. It is composed.

Here, the substrate 121 is preferably formed using a transparent material including sapphire, in addition to sapphire, zinc oxide (ZNO), gallium nitride (GaN), silicon carbide (silicon carbide: SiC) and aluminum nitride (AlN).

Here, a buffer layer (not shown) may be formed between the substrate 121 and the n-type semiconductor layer 122 to improve lattice matching therebetween, and the buffer layer (not shown) may be formed of GaN or AlN / GaN. Can be.

In this case, the n-type semiconductor layer 122 may be made of GaN or GaN / AlGaN doped with n-type conductive impurities, Si, Ge, Sn, etc. are preferably used as n-type conductive impurities, for example. Si is mainly used.

In addition, the p-type semiconductor layer 124 may be made of GaN or GaN / AlGaN doped with a p-type conductive impurity, Mg, Zn and Be is preferably used as the p-type conductive impurity, for example, Mg is mainly used.

In the LED chip 120, a portion of the p-type semiconductor layer 124 and an active layer 123 are removed by mesa etching so that a portion of the n-type semiconductor layer 122 is exposed. Accordingly, the p-type semiconductor layer ( 124 and the active layer 123 are formed on a portion of the n-type semiconductor layer 122.

Accordingly, the n-type electrode 125 is formed at one corner of the exposed n-type semiconductor layer 122, and the p-type electrode 126 is formed by the “top-top” method formed on the p-type semiconductor layer 124. The electrodes are arranged, to form a horizontal LED chip 120.

The active layer 123 may be a GaN-based single quantum well structure (SQW) or a multi quantum well structure (MQW), and a quantum structure of a super lattice (SL) thereof. As such, the quantum structure of the active layer 123 may be formed by combining various GaN-based materials, and as an example, AlGaN, AlNGaN, InGaN, or the like may be used.

When an electric field is applied to the active layer 123, light is generated by the coupling of the electron-hole pair.

Accordingly, when the voltage is applied between the P-type electrode 126 and the n-type electrode 125, the LED chip 120 may have holes and electrons as the P-type semiconductor layer 124 and the n-type semiconductor layer 122, respectively. When the electrons are injected, holes and electrons recombine in the active layer 123, and the surplus energy is converted into light and emitted to the outside through the substrate 121.

In this case, the LED chip 120 may generate blue, red, green, and UV wavelengths, and the LED chip 120 generating two or more wavelengths may be configured together.

The LED chip 120 is seated on the heat dissipation slug 110, and a pair of positive / cathode electrode leads 140a and 140b electrically connected to the heat dissipation slug 110 through the LED chip 120 and the wire 160. ) Is provided and exposed to the outside of the heat radiation slug 110.

At this time, the heat dissipation slug 110 on which the LED chip 120 is seated preferably forms a reflective surface by forming a surface of a material having a high reflectance in order to increase the efficiency of light emitted from the LED chip 120.

In addition, the pair of positive / cathode electrode leads 140a and 140b are electrically connected to current supply means (not shown) for supplying an operating current provided externally.

The fluorescent layer 130 is positioned above the LED chip 120 to generate light of a specific color.

Here, the phosphor layer 130 is formed by mixing the phosphor 170 in the transparent resin, the transparent resin transmits the light generated from the LED chip 120 and the light emitted by the phosphor 170 and the phosphor 170 is stably Any material that can be dispersed can be used.

For example, the transparent resin may be formed of any one of polymethyl methacrylate (PMMA), polystyreneene, polyurethane, epoxy, and silicone resin, which are acrylic transparent resins. .

The phosphor 170 is for converting wavelengths and is any one of yellow, red, and green phosphors. The phosphor 170 of the phosphor layer 130 is determined according to the light emission wavelength of the LED chip 120.

That is, the phosphor 170 capable of realizing white light by converting light emitted from the LED chip 120 is used.

For example, when the LED chip 120 is a blue LED chip, the phosphor 170 of the fluorescent layer 130 uses a yellow phosphor. Yellow phosphor uses YAG: Ce (T3Al5O12: Ce) -based phosphor, which is a yttrium (Y) aluminum (Al) garnet doped with cerium (Ce) having a wavelength of 530 to 570 nm, or a silicate-based yellow phosphor Preference is given to using.

As such, when the LED chip 120 generates blue light and the phosphor 170 of the fluorescent layer is a yellow phosphor, the light ultimately generated from the LED 100 becomes white light.

Therefore, light is emitted when a current is applied to the LED chip 120, and a part of the first emitted light of the LED chip 120 excites the phosphor 170 of the phosphor layer 130, and is caused by the phosphor 170. The white light is mixed with the wavelength-changed secondary light and the white light is emitted to the outside.

Here, the LED 100 of the present invention is characterized by further interposing a diffusion layer 200 between the LED chip 120 and the fluorescent layer 130.

The diffusion layer 200 is made of a bead mixed with a transparent resin, wherein the transparent resin is an acrylic transparent resin, polymethylmethacrylate (PMMA), polystyrene (polysterene), polyurethane (polyuretane), epoxy It may be formed of any one of (epoxy) and silicone resin (silicone resin).

Here, the beads have a size of 1 ~ 100nm, this diffusion layer 200 is formed to have a thickness of 1 ~ 3㎛.

The diffusion layer 200 has a refractive index of 1.5 to 2.0, the refractive index of the diffusion layer 200 has a refractive index similar to the LED chip 120.

Therefore, since the light emitted from the LED chip 120 is dispersed by the diffusion layer 200, it is possible to prevent the light emitted from the LED chip 120 from being partially concentrated.

In addition, since the diffusion layer 200 has a refractive index similar to that of the LED chip 120, the difference in refractive index between the LED chip 120 and the diffusion layer 200 is reduced, so that light emitted from the LED chip 120 is emitted from the LED chip 120. ) Is totally reflected at the boundary between the diffusion layer 200 and the diffusion layer 200 to minimize re-absorption or scattering by the LED chip 120.

Therefore, the amount of light incident on the fluorescent layer 200 can be increased, thereby improving light efficiency by reducing light loss.

In addition, since the diffusion layer 200 is interposed between the LED chip 120 and the fluorescent layer 130, it is possible to prevent the light generated in the fluorescent layer 130 from being reabsorbed by the LED chip 120. The light efficiency is improved.

In addition, the LED 100 of the present invention by the diffusion layer 200 is positioned so that the LED chip 120 and the phosphor 170 is spaced at a predetermined interval, thereby improving the luminous efficiency of the LED (100). .

That is, since the phosphor layer 130 including the phosphor 170 and the LED chip 120 are located close to each other, the efficiency of the phosphor 170 is reduced. Is to improve the efficiency.

In addition, since the LED chip 120 and the fluorescent layer 130 are positioned at regular intervals from each other, the phosphor 170 may be prevented from being deteriorated by heat generated when the LED chip 120 is driven. The degradation of the LED 100 may be prevented by the deterioration of the 170.

In addition, a lens 150 is disposed above the heat dissipation slug 110 to cover and protect the LED chip 120 and the wire 160, and to control the angle of the main outgoing light generated from the LED chip 120. .

Here, the lens 150 may be made of a synthetic resin or glass material, the synthetic resin polyethylene terephthalate (polyethylene terephthalate: PET), polyethylene naphthalate (polyethylene naphthalate), polymethyl methacrylate (PMMA), polycarbonate (polycarbonate) , Polystyrene, polyolefine, cellulose acetate, polyvinyl chloride, and the like.

Therefore, light is emitted when a current is applied to the LED chip 120, and a part of the first emitted light of the LED chip 120 excites the phosphor 170 of the phosphor layer 130, and is caused by the phosphor 170. The white light is mixed with the wavelength-changed secondary light, and the white light is emitted through the lens 150 to the main output light.

Table 1 below shows simulation results of measuring light efficiency of the LED 100 depending on the presence of the diffusion layer 200 between the LED chip 120 and the fluorescent layer 130.

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Sample 7 Presence of Diffusion Layer × 0 0 0 0 0 0 Light efficiency (lm) 31.318 31.584
(0.85% ↑) 31.573
(0.81% ↑) 31.548
(0.73% ↑) 31.466
(0.47% ↑) 31.406
(0.28% ↑) 31.357
(0.12% ↑)

Sample 1 is a simulation result of measuring light efficiency of a general LED that does not include a diffusion layer, and Sample 2 to Sample 7 measure light efficiency of an LED having a diffusion layer interposed between an LED chip and a fluorescent layer as in the first embodiment of the present invention. One simulation result.

Referring to Table (1), by interposing the diffusion layer 200 between the LED chip 120 and the fluorescent layer 130, it can be seen that the light efficiency is improved 0.12 ~ 0.85% compared to the case without the diffusion layer 200. have.

Since the diffusion layer 200 is interposed between the LED chip 120 and the fluorescent layer 130, the light emitted from the LED chip 120 is not partially concentrated, and the light emitted from the LED chip 120 is the LED chip. The total reflection at the boundary between the 120 and the diffusion layer 200 minimizes reabsorption or scattering of the LED chip 120, thereby increasing the amount of light incident on the fluorescent layer 130, thereby reducing light loss, thereby improving light efficiency. Because it can.

In addition, since the diffusion layer 200 is interposed between the LED chip 120 and the fluorescent layer 130, it is possible to prevent the light generated in the fluorescent layer 130 from being reabsorbed by the LED chip 120. The light efficiency is improved, and the LED chip 120 and the phosphor 170 are positioned at a predetermined interval by the diffusion layer 200, thereby preventing the degradation of the LED 100 due to the degradation of the phosphor 170. Because it can.

Here, the light efficiency may vary depending on the content of the beads in the transparent resin of the diffusion layer 200, when the beads have a refractive index of 2.5, and the transparent resin including the beads has a refractive index of 1.54, Sample 2 is a bead in the transparent resin When 1% is contained, the light efficiency is shown. Sample 3 is 3%, Sample 4 is 10%, Sample 5 is 20%, Sample 6 is 30%, Sample 7 was measured by varying the content of beads of 50%.

Referring to the simulation result thereof, it can be seen that the light efficiency of the LED 100 is improved as the number of beads in the transparent resin is contained.

Therefore, the LED 100 of the present invention is preferably such that 1 to 3% of the beads contained in the transparent resin of the diffusion layer 200.

Table 2 below shows simulation results of measuring light efficiency of the LED 100 according to the refractive index of the beads of the diffusion layer 200.

Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Presence of Diffusion Layer × 0 0 0 0 Bead refractive index × 2.5 2.0 1.54 1.5 Resin Refractive Index 1.54 Bead content One% Light efficiency (lm) 31.318 31.584
(0.85% ↑) 31.591
(0.87% ↑) 31.590
(0.87% ↑) 31.599
(0.90% ↑)

Sample 1 is a simulation result of measuring light efficiency of a general LED that does not include a diffusion layer, and Sample 2 to Sample 5 measure light efficiency of an LED having a diffusion layer interposed between an LED chip and a fluorescent layer as in the first embodiment of the present invention. One simulation result.

Referring to Table 2, it is understood that the refractive index of the beads contained in the transparent resin of the diffusion layer 200 is large, but the variation thereof is not large, and the refractive index of the beads does not significantly affect the light efficiency of the LED 100. Can be.

As described above, the LED 100 according to the first embodiment of the present invention is interposed with the diffusion layer 200 between the LED chip 120 and the fluorescent layer 130, the light emitted from the LED chip 120 The light emitted from the LED chip 120 is not partially concentrated and is totally reflected at the boundary between the LED chip 120 and the diffusion layer 200 to minimize reabsorption or scattering of the LED chip 120, thereby reducing the fluorescent layer 130. The light efficiency can be improved by increasing the amount of light incident on the?

In addition, the LED 100 of the present invention by the diffusion layer 200 is positioned so that the LED chip 120 and the phosphor 170 is spaced at a predetermined interval, thereby improving the efficiency of the phosphor 170, the phosphor 170 By the deterioration of the LED 100 can be prevented from deepening.

3A to 3B are cross-sectional views of a general LED implementing white light according to a second embodiment of the present invention.

Here, in order to avoid overlapping description, the same reference numerals are assigned to the same parts which play the same role as the above-described first embodiment, and only the characteristic contents to be described in the second embodiment will be described.

As shown, the LED 100 according to the second embodiment of the present invention includes an LED chip 120 that emits large light and a lens 150 covering the LED chip 120.

Looking at each of these in detail, first, the LED chip 120 is seated on the heat dissipation slug 110, a pair of quantity / electrically connected to the heat dissipation slug 110 through the LED chip 120 and the wire 160, etc. Cathode electrode leads 140a and 140b are provided and exposed to the outside of the heat radiation slug 110.

In addition, the pair of positive / cathode electrode leads 140a and 140b are electrically connected to current supply means (not shown) for supplying an operating current provided externally.

At this time, the diffusion layer 200 is located on the LED chip 120, the diffusion layer 200 is made of a bead mixed with a transparent resin, where the transparent resin is an acrylic transparent resin polymethylmethacrylate (polymethylmethacrylate: PMMA) ), Polystyrene (polysterene), polyurethane (polyuretane), epoxy (epoxy) and may be formed of any one of the silicone resin (silicone resin).

Here, the beads have a size of 1 ~ 100nm, this diffusion layer 200 is formed to have a thickness of 1 ~ 3㎛.

The diffusion layer 200 has a refractive index of 1.5 to 2.0, the refractive index of the diffusion layer 200 has a refractive index similar to the LED chip 120.

The lens 150 which covers the LED chip 120, the diffusion layer 200, the wire 160, and the like on the heat dissipation slug 110 and controls the angle of the main emission light generated from the LED chip 120. ) Is located.

At this time, the lens 150 is made of a mixture of silicon (not shown) and the phosphor 170, as shown in Figure 3a, or as shown in Figure 3b, the lens 150 made of silicon (not shown) Phosphor 170 may be coated on the inner wall of the substrate.

Therefore, the LED 100 generates light of a specific color.

For example, when the LED chip 120 generates blue light and the phosphor 170 mixed or coated on the lens 150 is a yellow phosphor, the light ultimately generated from the LED 100 becomes white light.

Thus, light is emitted when a current is applied to the LED chip 120, and the emitted light and the light emitted by the phosphor 170 mixed or coated on the lens 150 are mixed to emit white light to the outside.

Therefore, the LED 100 according to the second embodiment of the present invention may prevent the light emitted from the LED chip 120 from being partially concentrated by the diffusion layer 200, and the diffusion layer 200 may prevent the LED chip ( By having a refractive index similar to that of 120, the difference in refractive index between the LED chip 120 and the diffusion layer 200 is reduced, so that the light emitted from the LED chip 120 is totally reflected at the boundary between the LED chip 120 and the diffusion layer 200. Therefore, the LED chip 120 is minimized to be reabsorbed or scattered.

Therefore, the amount of light incident on the fluorescent layer 130 can be increased, thereby improving the light efficiency by reducing the light loss.

In addition, since the diffusion layer 200 is interposed between the LED chip 120 and the fluorescent layer 130, it is possible to prevent the light generated in the fluorescent layer 130 from being reabsorbed by the LED chip 120. The light efficiency is improved.

In addition, since the LED chip 120 and the phosphor 170 are positioned to be spaced apart from each other by a predetermined distance, the phosphor 170 may be prevented from being deteriorated by heat generated when the LED chip 120 is driven. The deterioration of the LED 100 by the deterioration of) can also be prevented.

4 is a cross-sectional view illustrating a liquid crystal display device according to an exemplary embodiment of the present invention.

As shown, the liquid crystal display device includes a liquid crystal panel 310 composed of first and second substrates 312 and 314 bonded to each other with a liquid crystal layer interposed therebetween, and a rear surface of the liquid crystal panel 310. The backlight unit 320 is provided to supply light from the.

The backlight unit 320 and the liquid crystal panel 310 have an edge surrounded by the support main 330, and a top cover 340 covering the upper edge and side of the liquid crystal panel 310 and a cover covering the rear surface of the backlight unit. The bottom 350 is coupled to the support main 330 so that both the backlight unit 320 and the liquid crystal panel 310 are integrally modularized.

Here, the reflector plate 325, the light guide plate 323, the LED assembly 400 provided on one side of the light guide plate 323, and the optical sheet 321 are stacked on the light guide plate 323, so that the backlight unit 320 is disposed. Will be achieved.

The LED assembly 400 described above is located at one side of the light guide plate 323 so as to face the light incident part of the light guide plate 323, and the LED assembly 400 has a plurality of LEDs 100 and a plurality of LEDs 100. The PCB 410 is spaced apart from each other.

In this case, the plurality of LEDs 100 is interposed between the LED chip 120 and the phosphor (170 of FIG. 3b) including a diffusion layer 200 containing a bead.

Accordingly, the LED 100 may prevent the light emitted from the LED chip 120 from being partially concentrated by the diffusion layer 200, and the diffusion layer 200 has a refractive index similar to that of the LED chip 120. Since the difference in refractive index between the LED chip 120 and the diffusion layer 200 is reduced, the light emitted from the LED chip 120 is totally reflected at the boundary between the LED chip 120 and the diffusion layer 200 to be reabsorbed by the LED chip 120. Minimization or scattering. Through this, the light efficiency can be improved.

In addition, the light generated in the fluorescent layer 130 can be prevented from being reabsorbed by the LED chip 120, thereby improving the light efficiency.

In addition, the LED 100 of the present invention is positioned by the diffusion layer 200 so that the LED chip 120 and the phosphor (170 of FIG. 3B) are spaced at a predetermined interval, and thus, the phosphor is formed by heat generated when the LED chip 120 is driven. Since the problem of deterioration of 170 of FIG. 3B can be prevented, the problem of deterioration of the LED 100 due to deterioration of the phosphor (170 of FIG. 3B) can also be prevented.

The light guide plate 323 spreads the white light incident from the LED assembly 400 evenly to a large area of the light guide plate 323 while propagating through the light guide plate 323 by several total reflections to provide a surface light source to the liquid crystal panel 310.

The light guide plate 323 may include a pattern of a specific shape on the rear surface to supply a uniform surface light source.

The reflecting plate 325 is positioned on the rear surface of the light guide plate 323, and reflects light passing through the rear surface of the light guide plate 323 toward the liquid crystal panel 310 to improve the brightness of the light.

The optical sheet 321 on the light guide plate 323 includes a diffusion sheet and at least one light collecting sheet, and diffuses or condenses the light passing through the light guide plate 323 to provide a more uniform surface light source to the liquid crystal panel 310. Make it incident.

In this case, the backlight unit 320 having the above-described structure is commonly referred to as a side light method, and a direct light for arranging a plurality of LED assemblies 400 side by side to the upper front surface of the reflector 325 according to the purpose. In this case, the light guide plate 323 may be omitted.

As described above, in the LED 200 of the present invention, the diffusion layer 200 is interposed between the LED chip 120 and the phosphor (170 of FIG. 3B), whereby the light emitted from the LED chip 120 is partially concentrated. In addition, since the diffusion layer 200 has a refractive index similar to that of the LED chip 120, the difference in refractive index between the LED chip 120 and the diffusion layer 200 is reduced, and the light emitted from the LED chip 120 is reduced. The total reflection at the boundary between the LED chip 120 and the diffusion layer 200 is minimized to be reabsorbed or scattered by the LED chip 120.

Therefore, the amount of light incident on the fluorescent layer 130 can be increased, thereby improving the light efficiency by reducing the light loss.

In addition, since the diffusion layer 200 is interposed between the LED chip 120 and the fluorescent layer 130, it is possible to prevent the light generated in the fluorescent layer 130 from being reabsorbed by the LED chip 120. The light efficiency is improved.

In addition, the LED chip 120 and the phosphor (170 of FIG. 3B) are positioned to be spaced apart from each other by a predetermined distance, thereby preventing the problem of deterioration of the phosphor (170 of FIG. 3B) by heat generated when the LED chip 120 is driven. As a result, the degradation of the LED 100 may be prevented by the deterioration of the phosphor (170 of FIG. 3B).

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

100: LED
110: heat radiation slug, 120: LED chip, 130: fluorescent layer
140a, 140b: Positive / cathode electrode leads
150: lens, 160: wire
170: phosphor
200: diffusion layer

Claims (10)

An LED chip mounted on the substrate;
A phosphor positioned on the LED chip to absorb light emitted from the LED chip to emit wavelength converted light;
A diffusion layer interposed between the LED chip and the phosphor and including a bead.
Light emitting diode comprising a.
The method of claim 1,
The diffusion layer is a light emitting diode having a refractive index of 1.5 ~ 2.0.
The method of claim 1,
The diffusion layer is a light emitting diode in which the beads are mixed with a transparent resin.
The method of claim 3, wherein
The bead is a light emitting diode contained 1 to 3% in the transparent resin.
The method of claim 3, wherein
The transparent resin is a light-emitting diode made of any one of polymethyl methacrylate (PMMA), polystyreneene, polyurethane, epoxy (epoxy) and silicone resin (silicone resin) which is an acrylic transparent resin.
The method of claim 1,
The phosphor is mixed in a transparent resin and positioned on the diffusion layer, the upper portion of the phosphor is a synthetic resin or glass material, the light emitting diode.
The method of claim 1,
The phosphor is made of a lens mixed with silicon or a light emitting diode coated on the lens inner wall.
The method of claim 1,
The LED chip is a blue LED chip, wherein the phosphor is a yellow phosphor, or a phosphor that is a mixture of red and green phosphors.
The method of claim 1,
The LED chip is a UV LED chip, the phosphor is a red (R), green (G), blue (B) phosphor of the light emitting diode.
An LED chip mounted on the substrate; A phosphor positioned on the LED chip to absorb light emitted from the LED chip to emit wavelength converted light; An LED assembly interposed between the LED chip and the phosphor and including a light emitting diode including a diffusion layer including a bead, a printed circuit board on which the light emitting diode is mounted, and positioned at one side of the LED assembly. A backlight unit including a light guide plate, a reflection plate positioned below the light guide plate, and an optical sheet seated on the light guide plate;
A liquid crystal panel mounted on the backlight unit;
A backlight unit and a support main body surrounding an edge of the liquid crystal panel;
A cover bottom formed in close contact with the support main back surface;
A cover main body and a cover bottom,
And the liquid crystal display device.
KR1020110137163A 2011-12-19 2011-12-19 Light emitting diode and liquid crystal display device using the same KR20130070043A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9851068B2 (en) 2016-05-03 2017-12-26 Ford Global Technologies, Llc Light-emitting diode lamps with thermally conductive lenses
KR20180047146A (en) * 2016-10-31 2018-05-10 엘지디스플레이 주식회사 Oxide phosphor, light emitting device and display device using the same
CN110246952A (en) * 2019-05-08 2019-09-17 格瑞电子（厦门）有限公司 A kind of LED wafer color-changing device
KR20190143243A (en) * 2018-06-20 2019-12-30 엘지디스플레이 주식회사 LED Module and backlight Module having the same and Display Device having the same
US10545375B2 (en) 2014-12-03 2020-01-28 Samsung Electronics Co., Ltd. White light emitting device and display device using the same

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10545375B2 (en) 2014-12-03 2020-01-28 Samsung Electronics Co., Ltd. White light emitting device and display device using the same
US11112648B2 (en) 2014-12-03 2021-09-07 Samsung Electronics Co., Ltd. White light emitting device and display device using the same
US11579485B2 (en) 2014-12-03 2023-02-14 Samsung Electronics Co., Ltd. White light emitting device and display device using the same
US11747673B2 (en) 2014-12-03 2023-09-05 Samsung Electronics Co., Ltd. White light emitting device and display device using the same
US9851068B2 (en) 2016-05-03 2017-12-26 Ford Global Technologies, Llc Light-emitting diode lamps with thermally conductive lenses
US10012358B2 (en) 2016-05-03 2018-07-03 Ford Global Technologies, Llc Light-emitting diode lamps with thermally conductive lenses
KR20180047146A (en) * 2016-10-31 2018-05-10 엘지디스플레이 주식회사 Oxide phosphor, light emitting device and display device using the same
KR20190143243A (en) * 2018-06-20 2019-12-30 엘지디스플레이 주식회사 LED Module and backlight Module having the same and Display Device having the same
CN110246952A (en) * 2019-05-08 2019-09-17 格瑞电子（厦门）有限公司 A kind of LED wafer color-changing device

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